Data display indicator



July 24, 1962 R. E. HAGER DATA DISPLAY INDICATOR 2 Sheets-Sheet 1 Filed Sept. 3, 1959 INVENTOR. Robert E. Hagar BY HIS ATTORNEY United States Patent Ofilice 3,946,542 Patented July 24:, 1962 3,046,542 7 DATA DISPLAY INDICATOR Robert E. Hager, Avalon, Pa., assignor to Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Filed Sent. 3, 1959, Ser. No. 837,971 6 Claims. (Cl. 340-347) This invention relates to data display indication systems, and more particularly to an indication system including a display indicator particularly adapted for use in a panel containing large numbers of indicators arranged in closely spaced rows or columns, and a binary code control circuit for controlling the display on-the indicator.

A principal object of my invention is to provide a new and improved data display indication system.

Another object of my invention is to provide a display indicator occupying a minimum amount of panel space and capable of displaying a maximum number of characters.

Another object of my invention is to provide a data display indication system which is rapid in operation.

In the attainment of the foregoing objects I provide an indication system including an indicator having means for positioning a belt by supplying energy in different binary code combinations through a control circuit to operate an energizing circuit for a motor. The motor is connected to drive means for advancing the belt. The control circuitry energizes a motor circuit to drive the motor until the belt is advanced to a position to display the symbol identified by the code signal supplied to the control circuit and thence opens the motor circuit to stop the motor. When the indicator is at rest the control circuit is energized selectively in the code pattern which identifies the position to which the indicator has been operated.

Other objects and advantages of the present invention will become apparent from the following description and the accompanying drawings in which like reference characters refer to like elements throughout, and in which:

FIG. 1 is an isometric view partly in cross section of one embodiment of my indicator, and

FIG. 2 is a diagrammatic viewof the circuits employed to drive the indicator of FIG. 1. I

I shall first describe an embodiment of an indication system according to my invention, and shall then point out the novel features thereof in the appended claims.

Referring to FIG. 1, my indicator comprises a casing 1 1 in the form of a relatively long, thin, parallelepiped. In one embodiment, casing 11 is about eight inches long, one inch thick and two inches high. A window 13 is formed on the front, or right-hand end as oriented in the FIG. 1, of casing 11. For simplicity in explanation the following description refers to the orientation of casing 11 as shown in FIG. 1, although it will be understoodthat the casing may be mounted in any position or orientation. Window 13 permits the viewing of symbols or characters formed or printed on a belt 15 movably mounted within casing 11. One end of belt 15 is aflixed or wound on a rotatable spool 17 mounted on the upper left-hand corner of casing 11. The other end of belt 15 is afixed or wound on a second rotatable spool 25 mounted" on casing 11 at a position near spool 17. Belt 15 extends from the upper surface of spool 17, along the length of casing 11 around an idler roller .19 mounted on the upper right-hand end of casing 11, downward along the front of the casing past window 13, around a second idler roller 21 mounted on the lower right-hand end of casing '11, up-

.Ward around the upper surface of a wheel 23 which is rotated by movement of belt 15, and thence to the lower surface of spool 25.

A gear wheel 18, concentric with spool 17, is rotatably mounted on a rod 31 which rod is affixed to the spool 17 As will be described hereinbelow, gear wheel 18 and gear teeth 25a, formed on the periphery of one side of spool 25, provide a means of rotating spools 17 and 25, respectively.

A motor 35, controlled by binary code data, as will be explained hereinafter, drives a worm 37 which engages a worm wheel 39 mounted on a friction clutch plate 43. Clutch plate 43 frictionally bears against the surface of the side of a gear wheel 45. Gear wheel 45 is in turn positioned to concurrently engage gear wheel 18 and gear teeth 25a to rotate the spools 17 and 25 in the same angular direction. Since belt 15 is positioned to extend from the upper surface of spool 17 to the lower surface 1 of spool 25, rotation of gear wheel 45 causes the belt to be wound on one spool as it is unwound from the other spool.

A normally biased or tensioned coiled leaf spring 29 has one end afiixed to rod 31; and its other endafiixed to a pin 33 which pin is affixed to the side of the gear wheel 18 and adjacent its periphery. Spring 29 thus main ,tains tension on belt 15 as will now be explained:

Spring 29 causes spool 17 to rotate in a relatively opposite direction with respect to the rotation of gear 18 whenthe belt is being unwoundfrom spool 17, and causes spool 17 to rotate an additional amount in the same direction as gear 18 when .belt 15 is being wound on spool 17. For example, assume that at a given time most of the length of belt 15 is wound on spool 17 and only a minimum length of the belt is wound on spool 25. Assume next that it is desired to unwind or play out the belt from spool 17 and wind it on spool 25. The instantaneous diameters on which the belt is being unwound and Wound are unequal, however, the speed of rotation of gear 18 is equal to the speed of rotation of gear 25a. Thus the belt 15 would normally tend to become slack; however, the force of spring 29 causes spool 17 to move a definite angular distance in a direction relatively opposite to the direction of rotation of gear 18 and maintains tension on belt 15. Likewise, assume that only a minimum length of belt 15 is wound on spool 17 and gear 18 is actuated to wind the belt on spool 17. The speed of rotation of gears 18 and 25a is the same so that the belt as it is unwinding from spool 25 would tend to become slack; however, the tension on spring 29 causes spool 17 to move an additional angular distance in the same direction as gear 18 is rotating which again causes tension to be maintained on belt 15.

A solenoid 47 is electrically connected in parallel with the motor 35 and is therefore energized concurrently therewith, see FIG. 2. Solenoid 47 has a central aperture 49 which receives a pair of aligned plungers or rods 51 and 53 which extend outwardly in opposite directions along the axis of solenoid 47. A stop 55 is inserted in aperture 49; and coil springs 57 and 59 are positioned between stop 55 and rods 51 and 53, respectively, to bias each of said rods outwardly. Internal stops, not shown,

out of aperture 49 by their respective springs.

Spaced wheel flanges 23d and 23a are connected by a center shaft 23]. Flanges 23d and 232 are rotated by the engagement of notches 15a in belt 15 with pins 23g on the periphery of the flanges. A plate 23a having symmetrically spaced detents 230 is also mounted on shaft 23f in the space between the Wheel flanges. Detents 23c receive or accommodate one end of rod 51 to provide a means of braking or stopping the rotation of wheel flanges 23d and 23a, as explained below. A helical gear 23b is also mounted on shaft 23) which helical gear drives a helical gear 61a formed on the end of a drive rod 61. A worm gear 61b is formed on the opposite end of rod 61. Gear 61b engages a rack 61 mounted on the upper side of a code card or plate 65 which plate rides on a guideway 66 and is normally biased toward the right by a coil spring 62 mounted on a rod 64 affixed to casing 11.

A brake arm 67 is pivoted at one end on a pivot pin 69 which is in turn mounted on casing 11. Brake arm 67 has a brake shoe 71 mounted on the free end thereof. Brake shoe 71 is contoured to conform to the periphery of spool 25. Rod 53 normally engages brake arm 67 to urge brake shoe 71 against the periphery of spool 25 to provide a braking action for spool 25. As is known, when solenoid 47 is energized rods 51 and '53 will be pulled toward the center of the rod, with rod 51 being pulled toward the left and rod 53 being pulled toward the right. When rod 51 is pulled toward the left it disengages from detents 23c to permit wheel 23 to be rotated. When the rod 53 is pulled toward the right it permits the brake arm 67 to descend and thus disengage brake shoe 71 from contact with spool 25 to permit the spool to rotate freely.

When solenoid 47 is deenergized, rod 53 moves outwardly and causes brake shoe 71 to engage spool 25 and the spool is braked. At the same time rod 51 also moves outwardly and engages detents 23c, stopping wheel 23 and belt 15 at a desired position. After braking, any further rotation of motor 35 will not affect the positioning of the spools 25 and 17 since the clutch plate 43- will slide on the fiat side surface of gear wheel 45.

A plurality of aligned brushes 75 mounted on leaf springs are arranged to make contact with the commutator or code plate 65. Brushes 75 are electrically connected to control circuitry shown in FIG. 2. Commutator or code plate 65 includes two conductive surfaces A and B which are insulated from one another in an interleaved pattern such that at varying positions of the code plate 65 the brushes 75 are contacting the surfaces in different combinations whereby different combinations of potentials are applied to the brushes as explained in more detail hereinbelow.

A block diagram of the electrical circuitry for controlling the indicator of FIG. 1 is shown in FIG. 2. As indicated by the arrows in FIG. 2, motor 35 moves the code plate 65 relative to the electrical brushes 75 designated individually as, B1, B2, B4, B8, and or 1). As can readily be appreciated, when the plate 65 reaches the extreme limits of its travel in one direction the rotation of the motor 35 has to be reversed in order that the code plate 65 move in the opposite direction. The directional control 36, in one embodiment, comprises a switch unit 36a which is mechanically actuated when plate 65 moves to its extreme limits. When the switch unit 36a is actuated the connections to the motor 35 are reversed to cause the motor to reverse its direction of rotation to drive the code plate 65 in an opposite direction.

Conductive surface A of code plate 65 is connected by brush (0) and lead 85 to one terminal of an Or gate 140 for purposes explained hereinbelow; and, conductive surface B of code plate 65 is connected by brush (-1- or 1) and lead 98 to the positive terminal of battery 83. For convenience in explanation the positive terminal of battery 83 will be assumed to be at a potential of 1 volt although it can, of course, be any voltage desired. Movement of code plate 65 causes the conductive surfaces A and B to be connected to brushes B1, B2, B4 and B8 in the order listed in the following chart:

TABLE I Position and Position and Symbol Belt 15 Brushes Symbol Belt 15 Brushes 13132 miss 131132 B4138 1 0 0 0 1 1 1 0 O 1 0 0 0 0 O 1 1 1 0 0 1 O 0 1 0 0 l. 0 0 1 0 l l 0 1 0 1 1 0 1 0 1 1 0 0 0 l l In the chart, under the brushes B1, B2, B4 and B8 the numeral 0 indicates a connection to the conductive surface A on plate 65 which surface is connected through the ((1) brush to Or gate 140, and the numeral 1 indicates a connection to the conductive surface B on plate 65 which surface is connected to the positive terminal of the battery. The output from brushes B1, B2, B4 and B8 is connected through leads 81, 82, 84 and 88, and leads 111a, 112a, 114a and 118a to And gates 121, 122, 124 and 128, respectively.

The control circuitry for the indicator will now be described. It should initially be pointed out that the individual components per se shown in block form in 'FIG. 2, namely the gates G, the multivibrators F/F, the And gates, the Dr gates, the driver amplifier, the pulse and clock sources, and the delay network are components well known in the art, see for example, Pulse and Digital Circuits by Millman and Taub, published by McGraw Hill Book Co., Inc., New York, N.Y. The structure of individual components per se does not form a part of the present invention.

A binary code data input, from any suitable device known in the art, is connected through terminals 10; 20, 40 and respectively to each of the system input gates labeled G and numbered 91, 92, 94 and 98. The output of a clock pulse source 93 is connected through a com- 'nion lead 95 or actuate gates G. As is known, code data arriving at the gate which is coincident with a clock or timing pulse passes through the respective gate to the remainder of the control circuitry.

The output from each of the gates 91, 92, 94 and 98 is connected directly to respective bi-stable or flip-flop multivibrators labeled F/F and numbered 101, 102, 104 and 108. A reset pulse source 97 is connected to the multivibrators through a common lead 86. The clock pulse source 93 and the reset pulse source 97 are timed so that a pulse from reset source 97 resets the multivi brators to their initial state before gates G are actuated by clock pulse source 93 to permit new data to be coupled to multivibrators F/F.

pulse source 96 may be employed to actuate the multivibrators as well as the gates G. As is known, this may be accomplishing by providing a direct connection from the alternate clock source 96 through lead 86 to multivibrators F/F to reset the multivibrators to an initial condition. The same pulse which resets multivibrators F/F is connected through a delay network 99 to gates G through lead 95 to open gates G to admit new'data to the system.

The mechanical portion of the indicator cannot be operated at rates equivalent to the rate at which data is delivered to the indicator from high speed computers and electronic data handling systems, so the multivibrators F/F provide means for accepting high speed, low voltage level input data. Further, since the input data can be accepted and registered in the multivibrators F/F at a high rate of speed, the input data need not be applied for the total time the indicator takes to position itself.

Each of the multivibrators 10 1, 102, 104 and 108 is connected by a pair of leads 111a, 111b; 112a, 112b; 114a, 1141); and 118a, 118b to And gates 121, 122, 124 and 128, respectively. As is well known, And type gates pass a signal only when all, in this case both, of its inputs are similar.

Each multivibrator F/ F has two conductingconditions or states corresponding to a binary output of 0 or 1. In the initial or first condition, each multivibrator provides an output of 0 (zero) volt to its output lead labeled a and an output of 1 volt to its output lead labeled b. Conversely, when in its second condition, each multivibrator F/F provides an output of 1 volt to its output lead a and an output of 0 (Zero) volt to its output lead 11. For example, when multivibrator 101 is in its initial condition, an output of 0 (zero) volt is provided to lead 111a and an output of l vol-t is provided to lead 111b. When in its second condition multivibrator 1 provides an output of 1 volt to lead 111a and an output of 0 (zero) volt to lead -111b.

As noted above, brushes B1, B2, B4 and B8 connect either 0 or 1 volt to leads 111a, 112a, 114a and 118a, respectively, and as will be appreciated each And gate will be opened to pass a signal only when the potential on the associated lead b, due to the output of the associated mult-ivibrator, is equal to the potential coupled through the respective brush to the associated lead a.

The output of the And gates 121, 122, 124 and 128 are connected in parallel through leads 131, 132, 134 and 138 to Or gate 140. Lead 85 is an additional input lead from brush (0) to Or gate 140. As is known, Or gate 140 will be enabled to pass a signal as long as it receives an input on any of its input leads.

The driving circuit for motor 35 includes driver amplifier 141 which has one terminal connected to the negative side of battery 83 and the other terminal connected through lead 142 and switch 36a to motor 35. The other side of motor 35 then connects through switch 36a to the positive side of battery 83. The output of Or gate 140 is coupled to the control electrode, not shown, of driver amplifier 141 to control the operation or energization of motor 35 and of the solenoid 47.

The operation of the system will now be briefly described. Initially the indicator is in a position as shown in the drawing with brushes 0, B1, B2, B4 and B8- touching the edge of the conductive surface A, and brush or 1) touching conductive surface B. A reset pulse is first coupled from reset pulse source 97 to multivibrators F/F through lead 86 which shifts the multivibrators to an initial state in which the voltage on each of the multivibrator output leads labeled a is 0 (zero) volt and the voltage on each of the output leads labeled b is 1 volt. Next a clock pulse is coupled from clock pulse source 93 through lead 95 to input gates G. If concurrently a binary code input, of say, 0001 corresponding to the numeral 8, see Table I, is received at terminals 10, 20, 40 and 80 (terminals 10, 20 and 40 receive a binary input 0, and terminal 80 receives a binary input 1), the gates G will pass the binary signal to each of their respective multivibrators F/F. The outputs of multivibrators 181, 10 2 and 104 will remain the same since a binary O input will not change the state of the multivi bra-tors. However, a binary 1 input to multivibra-tor 108 will shift its conducting state with the output on lead 118a being 1 volt and the output on lead 118b being 0 (zero) volt. The 1 volt output on lead 118a will be connected through lead 88, brush B8, conductive surface A, brush (0), and lead 85 to Or gate 140. Or gate 140 willthen open to pass a signal to driver amplifier 141m energize solenoid 47 and operate motor 35. Solenoid 47 when energized pulls rod 53 to release brake arm 67 and disengages rod 51 from detents 23c in wheel 23. Motor 35 when operated drives, spools 17 and 25 through clutch 43 to advance belt 15. The advancing of belt causes wheel 23 to rotate. As wheel 23 rotates, its center shaft 23 drives rod 61 which in turn moves code plate 65 toward the left, as oriented in the drawings (brushes move relatively to the right). The output from multivibrator 108 will continue to be coupled to Or gate 148 until brush B8 passes from conductive surface A to conducting surface B which is at'the position designated by the numeral 8 on code plate 65. At numeric position 8 on code plate 65 the circuit connection from multivibrator 108 to Or gate 140 is broken and interrupts the signal to driver amplifier 141 in the operating circuit of motor 35 and solenoid 47. Deenergization of solenoid 47 causes rod 53 to actuate brake arm 67 to stop spool 25 and rod 51 to engage detents 230 in wheel 23. Belt 15 is thus brought to a stop at the position displaying the numeral 8 at window 13, FIG. 1. As noted, any overtravel of motor 35 is compensated for by friction clutch 43, as is well known in the art.

Assume in a second case that brushes 75 are at a position indicated by the numeral 8 on code plate 65 and a. new indication is to be entered into the indicator. As before, clock pulse source 93 and reset pulse source 97 are timed such that before clock pulse source 93 opens gates G to admit new data to the indicator reset, source 97 pulses the mult-ivibrators F/F to reset the multivibr-ators to their initial condition. The binary code for decimal numeral 8 is 0001 so that for numeral 8 multivibrators 10 1, 102 and 104 are in an initial conducting condition in which each of the leads labeled a have a 0 (zero) volt output and each of the leads labeled b have a 1 volt output; consequently, a reset pulse at this point does not affect them. However, when the system is indicating the numeral 8, multivibrat-or 108 is in a conducting condition in which lead 118a has a 1 volt output and lead 11812 has a 0 (zero) volt output. The reset pulse will thus shift multivibrator 108 to its initial condition with lead 1180: having a 0 (zero) volt output and lead 118b having a 1 volt output.

Assume in the second case, that the new data to the system is a binary code input of 0000* corresponding to the decimal numeral 0 and consequently position 0 on code plate 65. When gates G are opened by pulse source 93, multivibrator 108 receives a binary 0 input which causes multivi-b-rator 108 to remain in its initial conducting condition as reset by source 97. At numeric position 8, a 1 volt potential is connected from the positive terminal of battery 83, through lead- 90, brush or 1), conductive surface B, brush B8, lead 88 and lead 118a to And gate 128. Thus at this position on the code plate 65 and in this conducting condition of multivibrator 108, both lead 118:: and lead 118]; connect a 1 volt input to And gate 128 and cause the gate 128 to pass a signal to and through Or gate 140 to driver amplifier 141. Amplifier 141 in turn energizes solenoid 47 and operates motor 35 to move belt 15 and code plate 65. Code plate 65 will be moved to the left to the end limit of its travel where the code plate contacts switch 36a to reverse the rotation of motor 35 and start plate 65 moving to the right. As soon as brush B8 passes from conductive surface B to conducting surface A (at numeric position 7), the 1 volt potential connected from battery 83 through lead will be interrupted and gate 128 will close thus tending to stop the operation of motor 35 to cause code plate 65 to stop its movement. However at numeric position 7, a 1- volt potential will be connected from battery 83 through lead 90, brush or 1), conducting surf-ace B,

' brush Bl, lead 81, and lead 111a to And gate 121. Since B, one or more of the intermediate brushes B1, B2, Ed and B8, their respective leads 81, 82, 84 and 88, the respective output lead labeled a of the multivibrators F/F, one or more of the And gates, one or more of leads 131, 132, 134 and 138 and Or gate 140 to provide a positive potential to driver amplifier 141. The second path may be traced from an output lead labeled a of one or more of the multivibrators F/F, through one or more of leads 81, 82, 84 and 88, one or more of the respective intermediate brushes B1, B2, B4- and B8,

conductive surface A, brush lead, 85 and Or gate 140 to provide a positivepotential to driver amplifier 141.

Another circuit at numeric position 7 for providing a 1 volt potential to an And gate is through conducting surface B, brush B4, lead 84 and lead 114a to And gate 124. Similarly at numeric position 6, brush B2 will connect a 1 volt potential to And gate 122. As code plate 65 continues to move to the right, one or more of the And gates will thus be opened to pass a signal to drive motor 35 until the brushes move to numeric position 0 on code plate 65. At numeric position 0, brushes B1, B2, B4 and B8 will connect a 0 volt potential to leads 111a, 112a, 114a and 118a; respectively. Since at this time all the multivibrators F/F are in an initial conducting condition, the output on each of leads 111b, 112b, 11412 and 11812 is 1 volt which is diiterent than the voltage now on leads 111a, 112a, 114a and 1186:, respectively, so that all the And gates will stop conducting causing the motor 35 to stop and solenoid 47 to be deenergized.

Assume, for example, in a third case that brushes 75 are at numeric position 8 and the new binary input data to the system is 0010 corresponding to the numeral 4. 'Multivibrators 101, 102 and 108 will remain in their initial condition as reset by source 97 in which the potential on each of leads 111a, 112a and 118a is 0 (zero) and the potential on leads 111b, 1121) and 11% is 1 volt. Multivibrator 104 will, however, shift to its other conducting condition in which lead 114a will have a 1 volt output and lead 114b will have 0 volt output. As in the second case above, at numeric position 8 a 1 volt potential is connected from the positive terminal of battery 83, through the circuit previously traced to cause And gate 128 to pass a signal to and through Or gate 140 to driver amplifier 141 to actuate motor 55. Initially the operation and movement of code plate 65 is similar to that described above for the assumed second case in which code plate 65 moves toward numeric position 0. However as the brushes move to numeric position 4, brushes B1, B2 and B8 connect a 0 (Zero) volt output through leads 111a, 112a and 118a to And gates 121, 122 and 128, respectively. And gates 121, 122 and 128 will thus be closed. Also, at numeric position 4, brush B4 contacts conductive surface B and connects a 1 volt potential to lead 114a from battery 83 through the circuit previously traced and since the potentials on leads 114a and 11411 are 1 and 0, respectively, And gate 124 is also closed. Further, Or gate 140 is also closed since at this point there is no electrical connection from lead 1 14a, brushes B4, conductive surface A and lead 85- to Or gate 140. Thus, motor 35 stops and a numeral 4 is indicated in window 13 of the indicator.

Assume in a fourth case that the brushes are at numeric position 8 and that the received binary code input causes multivibrator 1.08 to shift to a conducting condition in which lead 118a has a 1 volt output and lead 118!) has a 0 (zero) volt output. In this condition and since brushes 75 are already at'numeric position 8 the output of multivibrator 108 will have no effect in the movement of code plate 65. However, the input to the other multivibrator's will cause one or more of the other And gates 121, 122 and 124 to pass a signal in a manner, as discussed above, to cause the motor 35 to move code plate 65.

Although I have herein shown and described only one form of a data display indication system embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim l. A display indicator for a binary code signal system comprising a belt movable to a plurality of selectable positions in response to code signals, motive means for advancing said belt, control means for said motive means, a code plate having two conductive surfaces insulated from one another and forming a varied interleaved pattern, a plurality of spaced brushes for contacting said conducting surfaces, means for moving said code plate relative to said brushes in accordance with the advancement of said belt, the first of said brushes being connected to said control means, the last of said brushes arranged to be connected to a source of potential and the intermediate ones of said brushes being connected through said two conductive surfaces in varying combinations to said first and last brushes dependent on the relative position of said brushes on said plate, said control means comprising a plurality of electrical circuits, each circuit including a multivibrator having bistable conducting conditions and having a first and a second output lead, each said multivibrator being in a first and a second conducting condition in response to a binary input of zero and one respectively, said first output lead being at one potential during said first conducting condition and at a second potential during said second conducting condition and said second output lead being at said second potential during said first conducting condition and at a first potential during said second conducting condition, an And gate associated with each. multivibrator, said first and second output leads of each multivibrator being connected as inputs to a respective And gate, each of said first output leads also being connected to a respective intermediate brush, an Or gate, said And gates and said first brush being connected in parallel to said Or gate, each said And gate being rendered conductive when the voltage connected from the source through said last brush, said second conductive surface and one of said intermediate brushes to a first output lead of the associated multivibrator is equal to the potential on the second output lead of said associated multivibrator, said Or gate being rendered conductive,

in a first instance when one of said And gates is conductive and in a second instance when the voltage from said first output lead of a multivibrator connected through said other brushes, said first conductive surface, and said first brush to said Or gate is at the second potential, and said Or gate when conductive providing a signal to energize said motive means to advance said belt. 2. A display indicator comprising a belt carrying intelligence and movable to a plurality of selectable positions, a pair of spaced rotatable spools; reversible motor means for rotating said spools, one end of said belt being attached to one spool and the other end of said belt being afiixed to the other spool for positioning said belt by winding it on one spool and unwinding it from the other spool, a wheel including a stop means, means on said beltfor engaging and driving said wheel, a brake for said spools, a solenoid including a pair of plunger members extending from opposite ends of the solenoid, spring means biasing said plungers outwardly such that the first plunger engages said stop means to stop rotation of said wheel and the second plunger sets said brake to stop the rotation of said spools, electrical control means for controlling the operation of said motor and said solenoid, said solenoid when energized pulling said plungers inwardly to vfree said wheel and to release said brake, gear means driven by said wheel, a code plate movable by said gear means, said code plate comprising two conductive surfaces in- 'sulated from one another and forming a varied interleaved pattern, a plurality of brushes, a first of said brushes contacting said first conductive surface, a last of said brushes contacting said second conductive surface and the intermediate ones of said brushes contacting said first and second conductive surfaces in varying combinations dependent on the relative position of said code plate, said control means comprising a plurality of electrical circuits each responsive to binary data, first gate means for gating the output of said control means to said motor and said solenoid, said first brush arranged to be connected to a source of potential, said last brush being connected to said first gate means and said intermediate brushes being connected to respective ones of said circuits, second gate means, one for each of said circuits for gating the output of each of said circuits to said first gate means, said control means providing an output through a first electrical path in response to binarydata received, said first path extending from one of said circuits through one of said intermediate brushes, said first conductive surface and said first gate means to initiate operation of said motor and said solenoid, and said control means providing a second electrical path for continuing the operation of said motor in response to binary data received, said sec ond path extending from said source of potential through said last brush, said second conductive surface, one of said intermediate brushes and one of said circuit gates whereby said motor moves said belt and causes said plate to be moved to a position Where a correspondence is established between said binary data and the particular brush combination contacting said surfaces of said plate.

3. A display indicator comprising a belt carrying intelligence and movable to a plurality of selectable positions in response to binary data; a pair of spaced rotatable spools, reversible motor means for rotating said spools, the opposite ends of said belt being affixed to respective ones of said spools for positioning said belt by winding it on one spool and unwinding it from the other spool; a wheel including stop means, means on said belt for engaging and driving said wheel; a brake for said spools; a solenoid including a pair of plunger members extending from opposite ends of the solenoid, spring means biasing said plungers outwardly such that the first plunger engages said stop means to stop rotation of said wheel and the second plunger sets said brake to stop the rotationof said spools, said solenoid when energized pulling said plungers inwardly to free said wheel and release said brake, gear means driven by said wheel; a code plate movable by said gear means, said code plate comprising two conductive surfaces insulated from one another and forming a varied interleaved pattern, a plurality of brushes for contacting said first conductive surface, a first of said brushes contacting said first conductive surface, a last of said brushes contacting said second conductive surface and the intermediate ories of said brushes contacting said first and second surfaces in varying combinations dependent on the relative position of said code plate; and control means for controlling the operation of said motor and said solenoid, comprising separate electrical circuits each responsive to one bit of binary data, each circuit including a bistable multivibrator having a first and a second output lead, each said multivibrator being in a first and a second conducting condition in response to a binary input of zero and one respectively, said first output lead having a first potential and said second output lead having a second potential when the respective multivibrator is in a first conducting condition and the potentials on said output leads being alternated when said multivibrator is in a second conducting condition, and gates each having two inputs, said two output leads of each said multivibrator being connected as the two inputs of a respective And gate, each said intermediate brush being connected to the first output lead of a respective multivibrator, an Or gate, the

outputs of said And gates being connected in parallel to said Or gate, said first brush being connected to said Or gate and said last brush arranged to be connected to a source of potential, said motor being energized to move said belt to a new position when a pair of said first and second output leads has a potential applied thereto representative of a binary zero input to the associated multivibrator, and the voltage connected through a first electrical path extending from said source through said second brush, said second conducting surface, and the respective intermediate brush to said first output lead of said pair is equal to the potential on said second output lead of said pair, the associated And gate being opened and having an output when its two inputs are equal, an output from said associated And gate causing said Or gate to pass a signal to operate said motor to move said code plate to -a position at which said first electrical path is opened'due new position when a pair'of said first and second output leads has a potential applied thereto representative of a binary one input to the associated multivibrator, and the potential on said first output lead is connected through an intermediate brush, said first conductive surface and said first brush to said Or gate to pass a signal to operate said motor to move said co'de plate to a position at which said second electrical path is opened due to a correspondence of the received binary data and said brush combination.

4. A display indicator comprising a belt carrying intelligence and movable to a plurality of selectable positions, a pair of spaced rotatable spools, reversible mot-or means for rotating said spools, one end of said belt being attached to one spool and the other end being afiixed to the other spool for positioning said belt by winding it on one spool as it is unwound from the other spool, a wheel including stop means, means on said belt for engaging and driving said wheel, a brake for said spools, a solenoid including a pair of plungers extending from opposite ends of said solenoid, means biasing said plungers outwardly such that the first plunger engages a stop means to stop rotation of said wheel and the second plunger sets said brake to stop the rotation of said spools, said solenoid when energized pulling said plungers inwardly to free said wheel and release said brake, said solenoid and said motor arranged to be connected to a source of energy, gear means driven by said wheel, a code plate movable by said gear means, said code plate comprising twoconductive surfaces insulated from one another and forming a varied interleaved pattern, and a plurality of brushes for contacting said conductive surfaces, and means for electrically connecting said brushes'to external circuits which control the energization of said solenoid and said motor and thereby position said belt.

5. A display indicator comprising a belt carrying intelligence and movable to a plurality of selectable positions, a pair of spaced rotatable spools, reversible motor means for rotating said spools, one end of said belt being attached to one spool and the other end being aifixed to the other spool for positioning said belt by winding it on one spool as it is unwound from the other spool, a wheel including stop means, means on said belt for engaging and driving said wheel, said motor arranged to be connected to a source of energy, gear means driven by said wheel, a code plate'movable by said gear means, said code plate comprising two conductive surfaces insulated from one another and forming a varied interleaved pattern, and a plurality of brushes for contacting said conductive surfaces, and means for electrically connecting said brushes to external circuits which control the energization of said solenoid and said motor and thereby position said belt.

6. A display indicator comprising a belt carrying intelrotatable spool, the opposite ends of said belt being af- 1 1 fixed to respective ones of said spools for positioning said belt by winding it on one spool and unwinding it from the other spool, a rod axially afiixed to said first spool, a first gear wheel mounted concentric to said first spool, a coiled spring having one end aflixed to said rod and its other end aflixed to said first gear wheel for providing an angular force between said first spool and said first wheel, said second spool having gear teeth thereon, drive wheel means engaging said first gear wheel and said gear teeth on said second spool, an electric motor, a friction clutch for coupling said motor to said drive wheel means for rotatingsaid spools to position said belt, a belt driven Wheel, a pair of side flanges and a plate mounted intermediate said flanges, said flanges having outstanding pins, said belt including notches for engaging said pins and driving said wheel, said Wheel plate having detents on the periphery thereof, a brake for said spools, a solenoid including a pair of plungers one extending from each end of said solenoid, spring means biasing said plungers outwardly such that the first plunger engages one of the detents of said wheel to stop rotation of said wheel and the second plunger sets saidbrake to stop rotation of said spools, said solenoid when energized pulling said plungers inwardly to free said wheel and release said brake, gear means driven by said wheel, a code plate movable by said gear means, said code plate comprising two conductive surfaces insulated from one another and forming a varied interleaved pattern, electrical control circuits including a plurality of stationary aligned brushes for contacting said conductive surfaces, and means for electrically connecting said brushes to external circuits which control the energization of said solenoid and said motor in response to input data and thereby position said belt.

References Cited in the file of this patent UNITED STATES PATENTS 2,907,020 Champion Sept. 29, 1957 2,907,938 Hodgers et al Oct. 6, '1959 2,924,815 Reynolds Feb. 9, 1960 

